LOUISVILLE — For most horsemen, winning the Kentucky Derby is a once-in-a-lifetime dream. Win it twice and you’re on your way to the Hall of Fame. But twice in a row? That’s the stuff of legends.

Last year, trainer Doug O’Neill saddled his Santa Anita Derby winner, I’ll Have Another, to upset the Kentucky Derby at 15-1, embarking on a controversial and ultimately bizarre bid for the Triple Crown. Saturday, in the 139th Run for the Roses at Churchill Downs, O’Neill looks to repeat with another Santa Anita Derby winner, Goldencents.

With a victory, he would join a select fraternity of six other trainers — “Derby Dick” Thompson, “Plain Ben” Jones, his son Jimmy Jones, Lucien Laurin, D. Wayne Lukas and Bob Baffert — who have won the Derby back-to-back.

“It’s an incredible feeling,” O’Neill said. “When you think of the names, and the history that goes along with this great race, to be able to walk down that hall with some real greats, it’s unbelievable.

“Last year with I’ll Have Another, we were all fired up after winning the Santa Anita Derby, but still thought in our minds the Kentucky Derby was so far-fetched. You need such a great horse and so much racing luck to get it done. And so having got it done, this year’s dream just seems more real.”

There is another bit of history to be made if Goldencents wins. His rider, Kevin Krigger, a 29-year-old native of the U.S. Virgin Islands, would be the 12th black jockey ever to win the Derby, and the first since Jimmy Winkfield in 1902.

“[Krigger] has great chemistry with Goldencents,” O’Neill said, “and he’s got that ‘let’s bring it on’ [attitude] instead of being in awe of the whole thing, even though it’s been a long time since an African-American won the race. It’s time to make it happen again.”

A bay colt from the first crop of CashCall Futurity winner Into Mischief, Goldencents was purchased for a bargain $62,000 by a partnership that includes Rick Pitino, coach of this year’s NCAA basketball champion Louisville Cardinals — giving O’Neill, who hails from Michigan, a rooting interest in both teams in the finals. A star from the start, Goldencents romped by 7 1/4 lengths in his debut last summer at Del Mar, with assistant Leandro Mora listed as the trainer because O’Neill was serving a suspension at the time.

After running second in the Champagne and winning the Delta Downs Jackpot and the Sham, Goldencents got hooked in a speed duel in the San Felipe and tired to finish fourth. He needed a strong effort in the 1 1/8-mile Santa Anita Derby and delivered, stalking the pace before drawing clear to win by 1 1/4 lengths in 1:48.76, earning a Beyer Speed Figure of 105 that is tops in this year’s Derby field.

“He’s always shown us a lot of talent, and he never gets tired,” O’Neill said. “He’s got the speed and stamina to get a mile and a quarter. I’d be lying if [I said] I wasn’t worried with the race prior to the Santa Anita Derby, but we did some adjustments and it really paid off.”

What O’Neill did was to slow down Goldencents in his morning workouts, leaving him “with a lot more energy.” To that end, the colt all but walked through a six-furlong breeze in 1:16 1/5 last Thursday at Santa Anita before shipping to Kentucky.

Called “Champ” around the barn, Goldencents is “real laid back, not at all wild or skittish, just a class act,” O’Neill said. “That’s probably the biggest similarity [between Goldencents and I’ll Have Another]: They’re both very competitive and mentally tough.”

O’Neill’s journey through this year’s Triple Crown should be a lot smoother than last year’s bumpy ride. Following the Derby, reports surfaced about the California-based trainer’s history of violations, including a TCO2 overage (total carbon dioxide) in one of his horses, which resulted in a 45-day suspension.

After I’ll Have Another won the Preakness by a neck with a dramatic late charge, putting him in position to become the first Triple Crown winner in 34 years, the N.Y. State Racing and Wagering Board ordered that the Belmont Stakes horses had to be stabled together in a high-security detention barn the week of the race. The ruling obviously was directed at O’Neill, but it hardly mattered, as I’ll Have Another was scratched and retired with a tendon injury the day before the “Test of the Champion.”

Through it all, O’Neill turned the other cheek to his harshest critics and never ducked the media, while deflecting attention from himself to his horse.

“Last year, for every couple of pats on the back, we got like one kick in the groin,” he said. “So this year, we’re expecting maybe four or five pats on the back before getting the kick in the groin.

“But I would rather have a good horse and answer the tough questions than a slow horse and nobody asking anything.”